Antenna



Feb. 18, 1936. PQSTHUMUS ET A 2,031,065 ANTENNA Original Filed Sept. 19,1929 I INVENTORS KLAAS POSTHUMUS EBAYLTHASA VA DER POL ATTORNEY PatentedFeb. 18, 1936 UNITED STAES ATENT OFICE ANTENNA Original applicationSeptember 19, 1929, Serial No. 393,794. Divided and this applicationSeptember 21, 1933, Serial No. 690,355. In the Netherlands September 19,1928 5 Claims.

This invention is a. division of our copending application Serial No.393,794, filed September 19, 1929, and relates to antenna systems fortransmitting and receiving wireless signals. More particularly, theinvention provides an arrangement in which a pure directional effect isobtained by means of an aerial system utilizing a plurality of aerialsor radiators.

According to the invention the height of these aerials is substantiallyequal to or an odd multiple of the half wave length of the oscillationsto be transmitted or received, and the said aerials are energized suchthat the operative direction is at right angles to the plane in whichthe aerials are located.

In the preferred embodiment an arrangement is provided in which thespacing of the aerials is a half wave length and each aerial isconnected to one of two feeders present such that the energy in all theaerials is in phase. As an alternative, four feeders are provided andeach aerial is conected to two feeders such that the energy in all theaerials is in phase. An arrangement may be provided in which the spacingof the aerials is a half wave length and the aerials, which arealternately coupled in opposition, are connected to two central feeders.Alternatively, the spacing of the aerials may be an odd multiple of thehalf wave length and a single feeder is connected to all the aerialssuch that the energy in all the aerials is in phase.

The invention will be more clearly understood by reference to theaccompanying drawing, in which Figures 1 to 7 inclusive show someembodiments.

Figure 1 shows an antenna having two feeders 2, 4 to which the aerials 6are connected. The aerials are spaced one wave length apart so that theyare in phase. This is necessary to secure a directional effect at rightangles to the plane of the aerials and this is so in the case with allthe aerial systems claimed.

Figure 2 shows an antenna having likewise two feeders 2, 4.

In this case the aerials 8 are spaced a half wave length apart and asshown in the drawing are each only connected to one of the two feedersso as to ensure uniformity in phase.

The arrangement shown in Figure 3, is identical with that of Figure 2but for the width of the aerial system which is reduced by theinterconnection of coils ID in the feeders such that the spacing of theradiators or aerials is still rangement of Figure 3, the free ends ofthe aerials 8 shown in Figure 3 being connected to two feeders l4, l6 sothat the radiation of energy from the feeders, if any, is balanced bythe close proximity of a forward and a backward lead. The pairs offeeders l4, l4 and l6, it are preferably placed close together or theymay be separated by an even number of half Wave lengths to get properradiation addition in a direction perpendicular to their length.

Referring to Figure 5, all the aerials are fed from one single feeder l8and so are they in Figure 6 which shows the same antenna construction,but for the spacing of the aerials being very small so that in principleall the aerials are simultaneously in phase if their length is a halfwave length. That is to say, by bending adjacent half wave lengths, thecurrents therein, upon which radiation depends, are made to flow in thesame direction. As nevertheless the horizontal spacing is to be slightlytaken account of, the length of the aerials Will practically be slightlysmaller.

Referring to Figure 7, the aerials 2|] are arranged on either side oftwo central feeders 22; in order to ensure uniformity in phase at aspacing of a half wave length, the aerials must be a1- ternately coupledin opposition to the feeders.

We claim:

1. A directive antenna system comprising a two wire transmission line,the wires of said line being parallel to each other and separated adistance equal to an odd multiple of half the length of thecommunication wave, parallel radiators transverse of said wiresextending between said wires and connected thereto, said radiators beinglocated substantially one wave length apart whereby cophasalenergization is effected therein.

2. A directive antenna system comprising a two wire transmission line,the wires of said line being parallel to each other and separated adistance equal to an odd multiple of half the length of thecommunication wave, parallel radiators transverse of said wiresextending between said wires and connected thereto, said radiators beinglocated substantially one wave length apart whereby cophasalenergization is effected therein, another similar antenna system locatedclose to said first antenna system so arranged that the correspondingwires of both said transmission lines are in proximity to each other forthe cancellation of radiation from the wires of both of said lines, theradiators of said first antenna system being located substantiallyintermediate the radiators of said second antenna system.

3. A system in accordance with claim 2, char acterized in this, that theradiators of one antenna are separated from the adjacent radiators ofthe other antenna substantially one half wave length apart.

4. A directive antenna system comprising a two wire transmission line,the wires of said'line being parallel to each other and separated adistance equal to one half the length of the communication wave,parallel radiators transverse of said wires extending between said wiresand connected thereto, said radiators being located substantially onewave length apart whereby c0- phasal energization is efiected therein,another similar antenna system located close to said first antennasystem so arranged that the corresponding wires of both saidtransmission lines are in proximity to each other for the cancellationof radiation from the wires of both said lines, the radiators of saidfirst antenna system being located substantially intermediate theradiators of said second antenna system with respect to a.

single plane, adjacent radiators being separated one half wave lengthapart.

5. A directive antenna system comprising a two wire transmission line,the wires of said line being parallel to each other and separated adistance equal to an odd multiple of half the length of thecommunication wave, parallel radiators transverse of said wiresextending between said wires and connected thereto, said radiators beinglocated substantially one wave length apart whereby cophasalenergization is effected therein, another similar antenna systemparallel to said first antenna system and separated therefrom an evennumber of half wave lengths, the radiators of said first antenna systembeing located substantially intermediate the radiators of said secondantenna system with respect to a single plane.

KLAAS POSTI-IUMUS. BALTI-IASAR VAN DER POL.

